1. Field of the Invention
This invention relates to an information signal recording apparatus and more particularly to an apparatus having recording means for recording an information signal in a track on a record bearing medium and means for erasing the track.
2. Description of the Prior Art
Among apparatus of the above-stated kind, video tape recorders, video disc recorders, etc. which record and reproduce video signals on and from magnetic record bearing media have been well known.
The record bearing medium mentioned above permits recording not only of video signals but also of different data signals. Therefore, control data signals of varied kinds can be recorded in a part of the record bearing medium. With such control data thus recorded, various advantages can be obtained by controlling a reproducing device or a device connected to a printer, a facsimile device, etc.
However, in the case of a video signal and particularly a color video signal, an extremely wide recording band is necessary. For example, in the case where a chrominance signal is recorded in a low band and a luminance signal in a high band, if recording is made over a previously recorded video signal without erasing it, the chrominance signal component of the previous signal cannot be completely erased by the recording. In that event, therefore, the chrominance signal of the new video signal would be distorted and would result in uneven or smeary colors of a reproduced signal.
The data signal, on the other hand, permits recording of many data even within a narrow band width. Since the data signal are thus recorded in a narrow band width,any previously recorded data signal can be completely erased when a new data signal is recorded over the previously recorded data signal.
Furthermore, in cases where a record bearing medium is new or has no information signal recorded thereon, an erasing operation on the medium is meaningless in general. Therefore, erasing means is not necessary in that instance. However, without erasing means, it is impossible to completely erase a recorded signal which has a wide band width, such as in the case of a video signal as mentioned above. While, use of erasing means is thus sometimes necessary, arrangement to have an erasing operation always performed would result in a wasteful consumption of electrical energy. Moreover, in cases where one and the same head is to be used for both recording and erasing, in particular, unnecessorily long period of time will be required for recording.
It is a princrpal object of this invention to solve the above-state problems. It is another object of this invention to provide an information signal recording apparatus which is capable of always satisfactorily recording information signals and keeping electric energy consumption at a minimum.
It is a further object of this invention to provide an information signal recording apparatus which is capable of always satisfactorily recording information signals and shortening a period of time required in recording the information signal on the whole.
The above and other objects and features of the invention will appear more fully hereinafter from consideration of the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawings.